The invention relates generally to defibrillator electrodes and more specifically to an electrical circuit for generating pulses of energy at two stock electrodes of such a defibrillator.
A known form of defibrillator comprises an energy storage means such as a capacitor, and an operating switch which is closed in order for the energy stored in the capacitor to be supplied in pulse form to the shock electrodes of the defibrillator, when a patient is to be subjected to shock treatment thereby. The energy storage means can store energy in stepped or graduated quantities, and correspondingly graduated quantities of energy can be delivered, in dependance on the patient and the desired type of treatment. The amounts of energy delivered for external defibrillation may be between for example 20 and 320 Joules. Hitherto, from the point of view of patient safety, it was generally considered sufficient for the transfer of energy between the energy storage means or capacitor and the defibrillator electrodes to take place by way of an operating or working switch which is closed only for the duration of the defibrillation procedure. In other words, in that defibrillator design, the patient being treated is connected into the working circuit which comprises the capacitor and the operating switch. However, such an arrangement may involve a certain risk in regard to patient safety, particularly if there is a defect in the energy storage means or the switch.